I used to over engineer the air down pressure to manage my anxiety about airing down a heavy vehicle. After doing it a bunch of times over the years I go straight to 30 psi first. Then lower if needed for sand or really bad washboard. If there is a lot of sidewall abuse happening on the tires from rocks I'll keep it up at 30. I believe in getting out and walking around my vehicle more often than most people. This is yet another reason I lost all my friends with Jeeps and Toyotas as they are always in a hurry and hate it when I keep getting out. What I'm looking for is how much sidewall hits are the tires really taking, sometimes I think the trail is "just beating us up captain" and I get out and there isn't hardly a scuff on a tire, and I could air down more and sometimes the opposite happens. Same with temperature, if I know I'm real low (relatively) at say, 23 psi I'll put my hand on the sidewalls to see how hot they are, especially if the trail has opened up and I'm now going faster. If it's uncomfortable to keep my hand on the tire I'll air up some. I think I've only done this once.
My numbers for comparison.
Just under 10,000 lbs total weight
Not sure on the per axle weight.
285/75-16" General Grabbers on 2005 SMB issue aluminum rims
2005 SMB RB 4x4 6.0 PSD
A rocket on the pad is safe,
but it's not what rockets are built for.